From e011b04c6b2e31bdc46320e5d8a4f48715681f15 Mon Sep 17 00:00:00 2001 From: Neels Hofmeyr Date: Wed, 12 Jan 2022 02:58:02 +0100 Subject: libosmo-gtlv: add C code generator for IE structs and arrays Defining a protocol of message types with lists of IEs bears a lot of repetitive, copy-paste-error-prone writing out of data structures. Add a third layer to libosmo-gtlv, which allows helpful code generation. By non-repetitive data structures that briefly describe the protocol's messages and IEs, generate possibly repetitive IE list arrays and decoded-struct definitions automatically, avoiding grunt work errors. I tried C macros for this at first, but it became too convoluted. Generating C code that can be read and grepped makes things easier. A usage example is found in tests/libosmo-gtlv/test_gtlv_gen/. Related: SYS#5599 Change-Id: Ifb3ea54d2797ce060b95834aa117725ec2d6c4cf --- tests/libosmo-gtlv/test_gtlv_gen/gtlv_gen_test.c | 261 +++++++++++++++++++++++ 1 file changed, 261 insertions(+) create mode 100644 tests/libosmo-gtlv/test_gtlv_gen/gtlv_gen_test.c (limited to 'tests/libosmo-gtlv/test_gtlv_gen/gtlv_gen_test.c') diff --git a/tests/libosmo-gtlv/test_gtlv_gen/gtlv_gen_test.c b/tests/libosmo-gtlv/test_gtlv_gen/gtlv_gen_test.c new file mode 100644 index 0000000..ef5372c --- /dev/null +++ b/tests/libosmo-gtlv/test_gtlv_gen/gtlv_gen_test.c @@ -0,0 +1,261 @@ +/* + * (C) 2021-2022 by sysmocom - s.f.m.c. GmbH + * All Rights Reserved. + * + * Author: Neels Janosch Hofmeyr + * + * SPDX-License-Identifier: GPL-2.0+ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + * + */ + +#include +#include + +#include +#include +#include + +#include + +#include + +struct myproto_msg { + enum myproto_msg_type type; + union myproto_ies ies; +}; + +static void err_cb(void *data, void *decoded_struct, const char *file, int line, const char *fmt, ...) +{ + va_list args; + va_start(args, fmt); + //printf("ERR: %s:%d ", file, line); + printf("ERR: "); + vprintf(fmt, args); + va_end(args); +} + +static int myproto_msg_enc(struct msgb *dst, const struct myproto_msg *msg, const struct osmo_gtlv_cfg *cfg) +{ + struct osmo_gtlv_put gtlv = { + .cfg = cfg, + .dst = dst, + }; + + msgb_put_u8(gtlv.dst, msg->type); + return myproto_ies_encode(>lv, (void *)&msg->ies, msg->type, err_cb, NULL, myproto_iei_names); +} + +static int myproto_msg_dec(struct myproto_msg *msg, const uint8_t *data, size_t data_len, + const struct osmo_gtlv_cfg *cfg, bool ordered) +{ + struct osmo_gtlv_load gtlv; + if (data_len < 1) + return -EINVAL; + msg->type = data[0]; + gtlv = (struct osmo_gtlv_load){ + .cfg = cfg, + .src = { data + 1, data_len - 1 }, + }; + return myproto_ies_decode(&msg->ies, >lv, ordered, msg->type, err_cb, NULL, myproto_iei_names); +} + +void *ctx; + +struct myproto_msg tests[] = { + { + MYPROTO_MSGT_MOO, + { + .moo = { + .foo = 23, + .bar = { "twentythree" }, + }, + }, + }, + { + MYPROTO_MSGT_MOO, + { + .moo = { + .foo = 23, + .bar = { "twentythree" }, + + .baz_present = true, + .baz = { + .v_int = 2323, + .v_bool = true, + }, + }, + }, + }, + { + MYPROTO_MSGT_MOO, + { + .moo = { + .foo = 23, + .bar = { "twentythree" }, + + .baz_present = true, + .baz = { + .v_int = 2323, + .v_bool = true, + }, + + .repeat_int_count = 3, + .repeat_int = { 1, 2, 0x7fff }, + }, + }, + }, + { + MYPROTO_MSGT_MOO, + { + .moo = { + .foo = 23, + .bar = { "twentythree" }, + + .baz_present = true, + .baz = { + .v_int = 2323, + .v_bool = true, + }, + + .repeat_int_count = 3, + .repeat_int = { 1, 2, 0x7fff }, + + .repeat_struct_count = 2, + .repeat_struct = { + { + .v_int = 1001, + .v_bool = true, + .v_enum = R_A, + }, + { + .v_int = 1002, + .v_bool = false, + .v_enum = R_B, + }, + }, + + .nest_present = true, + .nest = { + .foo = 42, + .bar = { "fortytwo" }, + .baz = { + .v_int = 4242, + .v_bool = false, + }, + }, + }, + }, + }, + { + MYPROTO_MSGT_GOO, + { + .goo = { + .foo = 17, + + .bar_present = true, + .bar = { "gooei" }, + + .nest_count = 2, + .nest = { + { + .val_present = true, + .val = 0x0123456789abcdef, + .nest = { + .foo = 11, + .bar = { "eleven" }, + .baz = { + .v_int = 1111, + .v_bool = true, + }, + }, + }, + { + .val_present = false, + .nest = { + .foo = 12, + .bar = { "twelve" }, + .baz = { + .v_int = 1212, + .v_bool = false, + }, + }, + }, + }, + }, + }, + }, +}; + +int myproto_msg_to_str_buf(char *buf, size_t buflen, const struct myproto_msg *m) +{ + struct osmo_strbuf sb = { .buf = buf, .len = buflen }; + OSMO_STRBUF_PRINTF(sb, "%s={", get_value_string(myproto_msg_type_names, m->type)); + OSMO_STRBUF_APPEND(sb, osmo_gtlvs_encode_to_str_buf, &m->ies, 0, myproto_get_msg_coding(m->type), + myproto_iei_names); + OSMO_STRBUF_PRINTF(sb, " }"); + return sb.chars_needed; + +} + +char *myproto_msg_to_str(const struct myproto_msg *m) +{ + OSMO_NAME_C_IMPL(ctx, 256, "ERROR", myproto_msg_to_str_buf, m) +} + +void test_enc_dec(const char *label, const struct osmo_gtlv_cfg *cfg, bool ordered) +{ + int i; + for (i = 0; i < ARRAY_SIZE(tests); i++) { + int rc; + const struct myproto_msg *orig = &tests[i]; + struct myproto_msg parsed = {}; + struct msgb *msg; + + printf("\n=== start %s %s[%d]\n", label, __func__, i); + printf("encoded: %s\n", myproto_msg_to_str(orig)); + + msg = msgb_alloc(1024, __func__); + rc = myproto_msg_enc(msg, orig, cfg); + printf("myproto_msg_enc() rc = %d\n", rc); + printf("%s.\n", osmo_hexdump(msg->data, msg->len)); + + rc = myproto_msg_dec(&parsed, msg->data, msg->len, cfg, ordered); + printf("myproto_msg_dec() rc = %d\n", rc); + printf("decoded: %s\n", myproto_msg_to_str(&parsed)); + if (strcmp(myproto_msg_to_str(orig), myproto_msg_to_str(&parsed))) { + printf(" ERROR: parsed != orig\n"); + exit(1); + } + + msgb_free(msg); + printf("=== end %s %s[%d]\n", label, __func__, i); + } +} + +int main() +{ + ctx = talloc_named_const(NULL, 0, "test_gen_tlv"); + msgb_talloc_ctx_init(ctx, 0); + + test_enc_dec("t8l8v ordered", &osmo_t8l8v_cfg, true); + test_enc_dec("t8l8v unordered", &osmo_t8l8v_cfg, false); + + test_enc_dec("t16l16v ordered", &osmo_t16l16v_cfg, true); + test_enc_dec("t16l16v unordered", &osmo_t16l16v_cfg, false); + + talloc_free(ctx); + return 0; +} -- cgit v1.2.3